Automatic inductive reactance for welding circuits



Mmh 3 59, 1943. M. T. MOORE AUTOMATIC INDUCTIVE REACTANCE FOR WELDING CIRCUITS Filed April 2, 1941 2 Sheets-Sheet l Inventor mam T/Vaa/Pf v Attor i leiy March 30, 1943. T MOORE v 2,315,159

AUTOMATIC INDUCTIVE REACTANCE FOR WELDING CIRCUITS Filed April 2, 1941 2 Sheets-Sheet 2 Inventor A742,? 7. Moe/P:

A Home Patented Mar. 30, 1943 UNITED STATES PATENT OFFICE 1 2,315,159 1 I AUTOMATIC INDUCTIVE REAOTANCE FOR g wnnnmocmourrs g i Mark T. Moore, Kearney, Nebr. Application Apr-i112, 1941, Serial No. 386,526 4 Claims. @(01. 171-242) My invention relates to improvements in automatic inductive reactances for A. C. electric arc welding circuits, acting to stabilize and regulate the flow of current to the work, and the primary object of my invention is to provide a simple and emcient, arrangement of this character whose ac-- tion can be readily predetermined by easy adjustment.

Other important objects and advantages of a my invention will be apparent from a reading of the following description taken in connection with the appended drawings, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

In the drawings:

Figure l is a general side elevational view of tical sectional view taken through Figure 3 along h line 5-5.

Figure 6 is a transverse vertical sectional view taken through Figure 2along the line 5-5 and looking in the direction of the arrows.

Figure? is "an enlarged longitudinal vertical sectional view taken through the adjustable spring abutment. V

Figure 8 is an enlarged fragmentary longitudinal vertical sectional view taken through the screw support.

Referring in detail to the drawings, the numera1'5 generally designates the coil which comprises squared dielectric heads '6 and I spaced and connected by square cross section sheet iron tube 8 whose left hand end extends flush with the opening in the left hand head 6 and extends through and beyond the opening in the right hand head' I as clearly indicated in Figure 3 of the drawings. The tube 8 iswound with magnet wire in a number of turns and in a gauge suitable to the work to be performed, the winding 9 extending between the heads 6 and 1. As indicated in Figures 3 intogrooves in the side of the block III a indicated by the numerals II and I2 in Figure5 of the drawings.

Riveted or otherwise secured as indicated by the numeral i3 to the sidewalls of the sheet iron form 8 and extending beyond the head I are the standards 15 preferably formed of suitable metal and having horizontal elongated extensions I6 and [1, respectively, which project parallelly to the axis of the coil ,9 and are joined at their outer ends by a cross piece I8, thereby forming an elongated rectangular frame subsisting ata level above that of the coil 9. A reclining L-shaped cross member 19 connects the juncture of the upper ends of the standards I4 Circumposed on the screw Zlland on the tubular portion 23 of the support 22 is the expanding helical spring 24 which is also circumposed on thetubular threaded portion, 25 of the spring abutment which is generally designated 26 and which has a rectangular flange 21 whose lateral.

ends bear against the inner sides of the side members i6 and IT to preclude rotationof the abutment 26.

.The outer end of the screw 20 is provided with a counterbalanced handle 28 which is to be grasped and rotated to turn the screw2 0 to position the abutment 25 relative to the support 22 and thereby predetermine the compression of the spring 24 and hence the amount of magnetism which must be generated by'the coil 9 to measurably attract the core 29 into the tube 8, against the resistance of the spring 24.

The core 29 is generally rectangular in cross section as indicated in Figures 4 and 5 .of the drawings, being composed of upper and lower banks 3| and 32 of laminated iron disposed against the upper and lower sides of the horizontal bar 33 to which the banks are assembled by means of screws or bolts 34. The bar 33 has at its right hand end a vertical projection 35 which terminates in the support 22.

As indicated in Figure l of the drawings, the opposite ends of the coil 9, which are connected to binding posts 36 and 31 carried by the coil head 6 are respectively connected to the carbon or other welding element 38, and to the work 39, respectively, with the transformer 40 connected in between the corresponding end of the coil 9 and the said work 39, the transformer being energized from a suitable source of A. C. current (not shown). Thus it will be understood that the coil 8 is connected in series with the secondary of the welding transformer 40 and the electrode ll. The E. M. F. of the current is determined by the position of the laminated core 29 relative to the coil 9, the core 28 being capable of manual adjustrnent or setting and by magnetic force when in operation, the core being drawn into the coil 9 inan amount proportionate to the density of the current, against the resistance of the spring 24.

- When an arc is struck between the electrode ll and the work 39 the core 29 moves farther into the coil 9, the distance depending on the setting of the machine and the width of the arc. As the core 29 moves out of the coil after the arc is struck, the tension of the spring acting on the core moves the core back to aposition between that existing when the arc was struck and the original position, thereby' decreasing the magnetic flux and keeping the current nearly constant. This automatic regulating action of the device prevents the current from burning up the electrode when the rod is struck and provides a stabilized flow of current automatically during the welding operation. When the arc becomes wider the spring 24 moves the core 29 out of the magnetic field and the inductive reactance becomes less and the voltage rises while the amperage remains nearly constant, resulting in stabilized current flow. When the arc becomes shorter the core 29 is drawn farther into the magnetic field, the inductive reactance becomes greater, and the current voltage is caused to drop, while the amperage remains substantially constant, thus again exhibiting stabilized current regulation. By adjusting the screw 20 the device may be set to produce any desired welding heat within the range of the device, without the trouble of changing taps or connections. In this way the present device gives a wider range and finer settings than are available with present A. C. arc welding devices.

Although I have shown and described herein preferred embodiments of my invention, it is to be definitely understood that I do not wish to limit the application ofthe invention thereto, except as may be required by the scope of the subjoined means comprising spring means on saidframe mechanically resisting movement of said core toward said coil, and adjusting means on said frame for initially positioning said core relative to said coil and correspondingly determining the tension of said spring means, said frame comprising an element having spaced end members, said adjusting means comprising a screw rotatably extending through smooth openings formed in said end members, and means for rotating said screw, said spring means comprising a helical spring circumposed on said screw with one end thereof engaging an abutment threaded on said screw, said core having an element adjacent said screw and operatively engaging the opposite end of the spring.

2. In an automatic reactance to regulate the current in an arc welding circuit, a solenoid coil having a head at one end, a magnetizable core extending into said end of the solenoid coil through an aperture formed in said head, an elongated frame mounted to project from said head alongside of said core, a screw longitudinally journaled for rotation in portions of said frame, an abutment non-rotatably engaging a portion of said frame and through which said screw is threaded, whereby turning of the screw in opposite directions effects longitudinal movement of said abutment toward and away from one end of said frame, an element secured to project from said core toward said screw, and an expansible helical spring circuniposed on said screw between said element and said abutment to resist movement of said core into said solenoid coil, said screw being rotatable to tension or relax said spring.

3. In an automatic reactance for an electric arc welding circuit, a solenoid coil adapted for connection in said circuit, a solenoid core entering one end of said coil, means supporting said core for movement into and out of said coil, said support comprising a frame mounted at the said end of the coil and extending alongside of said core, said frame having longitudinally spaced members, a screw mounted on said members for rotation without substantial longitudinal movement relative to said members, an abutment threaded on said screw between said members, means on said frame preventing rotation of said abutment while allowing longitudinal movement along the screw when the screwis turned, an element projecting laterally from said core in alignment with a portion of said abutment, a helical spring compressed between said portion of the abutment and said element, and means for rotating said screw to adjust the compression of said spring.

4. In an automatic reactance as recited by claim 3, wherein-said laterally ,projecting element comprises a sleeve slidably receiving said screw.

MARK T. MOORE. 

